1. Field of the Invention
The present invention relates to a separable bottom-end-stop assembly of thermoplastic synthetic resin for a separable slide fastener.
2. Description of the Prior Art
U.S. Pat. No. 4,221,026 issued Sept. 9, 1980 discloses a separable bottom-end-stop assembly, for a slide fastener, of a so-called lateral insertion type. As reillustrated here in FIG. 6 of the accompanying drawings, this type of separable bottom-end-stop assembly comprises a pair of intercoupling male and female members A, B of thermoplastic synthetic resin mounted on adjacent bottom ends of opposed fastener stringers by molding. The male member A extends along an inner longitudinal edge of one stringer tape and has at its inner side a longitudinal projection F and at its lower end a pivot pin C. The female member B extends along an inner longitudinal edge of the other stringer tape and has at its inner side a longitudinal groove G receptive of the longitudinal projection F and, at a position near its lower end E, a support hole D opening obliquely inwardly for receiving the pivot pin C. For coupling the male and female members A, B together, the pivot pin C of the male member A is inserted in the support hole D of the female member B, and then the male member A is pivotally moved about the pivot pin C to cause the projection F to be laterally received in the groove G.
In production, a pair of opposed stringer tapes are clamped between a pair of upper and lower mold halves jointly defining a pair of mold cavities each having a contour corresponding to the shape of a respective one of the male and female members A, B. Then molten thermoplastic synthetic resin is injected into the mold cavities to form the male and female members A, B directly on the respective stringer tapes. At that time, the stringer tapes tend to become wavy in the mold cavities because the latter are hollow and hence there are no parts pressing the stringer tapes. As a result, the male and female members are molded on the wavy stringer tapes in such a manner that the latter are locally and irregularly exposed to the surface of the molded members, especially to the surface of the male member, which has only a limited thickness, thus impairing not only the appearance but the bending strength of the molded article.
If the male member were to have an increased thickness, the gap between upper and lower guide flanges of a slider must be increased; that is, the height of the guide flanges must be short. With such short guide flanges, smooth and correct coupling of opposed fastener element rows is difficult to achieve.